/*
 * $Header: /home/cvs/jakarta-tomcat-4.0/catalina/src/share/org/apache/catalina/realm/JAASCallbackHandler.java,v 1.1 2001/11/13 22:42:31 craigmcc Exp $
 * $Revision: 1.1 $
 * $Date: 2001/11/13 22:42:31 $
 *
 * ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * [Additional notices, if required by prior licensing conditions]
 *
 */


package org.apache.catalina.realm;


import java.io.IOException;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.NameCallback;
import javax.security.auth.callback.PasswordCallback;
import javax.security.auth.callback.UnsupportedCallbackException;


/**
 * <p>Implementation of the JAAS <strong>CallbackHandler</code> interface,
 * used to negotiate delivery of the username and credentials that were
 * specified to our constructor.  No interaction with the user is required
 * (or possible).</p>
 *
 * @author Craig R. McClanahan
 * @version $Revision: 1.1 $ $Date: 2001/11/13 22:42:31 $
 */

public class JAASCallbackHandler implements CallbackHandler {


    // ------------------------------------------------------------ Constructor


    /**
     * Construct a callback handler configured with the specified values.
     *
     * @param realm Our associated JAASRealm instance
     * @param username Username to be authenticated with
     * @param password Password to be authenticated with
     */
    public JAASCallbackHandler(JAASRealm realm, String username,
                               String password) {

        super();
        this.realm = realm;
        this.username = username;
        this.password = password;

    }


    // ----------------------------------------------------- Instance Variables


    /**
     * The password to be authenticated with.
     */
    protected String password = null;


    /**
     * The associated <code>JAASRealm</code> instance.
     */
    protected JAASRealm realm = null;


    /**
     * The username to be authenticated with.
     */
    protected String username = null;


    // --------------------------------------------------------- Public Methods


    /**
     * Retrieve the information requested in the provided Callbacks.  This
     * implementation only recognizes <code>NameCallback</code> and
     * <code>PasswordCallback</code> instances.
     *
     * @param callbacks The set of callbacks to be processed
     *
     * @exception IOException if an input/output error occurs
     * @exception UnsupportedCallbackException if the login method requests
     *  an unsupported callback type
     */
    public void handle(Callback callbacks[])
        throws IOException, UnsupportedCallbackException {

        for (int i = 0; i < callbacks.length; i++) {

            if (callbacks[i] instanceof NameCallback) {
                if (realm.getDebug() >= 3)
                    realm.log("Returning username " + username);
                ((NameCallback) callbacks[i]).setName(username);
            } else if (callbacks[i] instanceof PasswordCallback) {
                if (realm.getDebug() >= 3)
                    realm.log("Returning password " + password);
                ((PasswordCallback) callbacks[i]).setPassword
                    (password.toCharArray());
            } else {
                throw new UnsupportedCallbackException(callbacks[i]);
            }


        }

    }


}
